Our overall objective is to investigate biogenic amine systems in mammalian brain as they relate to neurologic disorders such as parkinsonism. Included are studies of the anatomy of the dopaminergic, noradrenergic, and serotonergic systems in the brains of primates. The relationship of biogenic amines and cyclic AMP systems is being studied in mammalian brain: in particular, the dopamine stimulated adenylate cyclase system of the mesolimbic system as well as the caudate, and the changes in these systems with denervation are being studied. The physiology of the amine metabolites, HVA, 5-HIAA, and MHPG, in the CSF and urine of patients with various neurologic disorders is under investigation. In vitro models of neuromelanin formation in dopamine are being studied. The effect of drugs that act on aminergic systems is being studied by use of the 2-L-deoxyglucose radioautography method to estimate regional glucose utilization. Finally, the histofluorescent properties of the noradrenergic and dopaminergic axons in mammalian brain are being used to study the process of regeneration and sprouting of axons in response to focal injury and deafferentation.